電壓穩定畢業設計

電子機電論文編號:JD191     字數:22916,頁數:56  

目 錄
摘要........................................................................ 1
目錄 ........................................................................3
第一章   緒論................................................................5
1.1 電壓穩定研究概述..........................................................5
1.1.1 電壓穩定問題的概念......................................................5
1.1.2 電壓穩定的分析方法 .....................................................5
1.2 切負荷對系統電壓穩定的作用................................................6
1.2.1 預防性切負荷措施........................................................6
1.2.2 校正性切負荷措施........................................................6
1.3 切負荷策略研究中的問題................................................... 6
1.4 本文的工作 ...............................................................7
第二章改進的潮流算法.........................................................9
2.1 引言..................................................................... 9
2.2. 系統模型 ................................................................9
2.2.1 發電機模型 .............................................................9
2.2.2 負荷模型................................................................11
2.2.3 網絡方程................................................................11
2.2.4 通用的微分－代數方程模型................................................12
2.3 潮流方程的求解............................................................13
2.3.1 方程的結構 .............................................................13
2.3.2 雅可比矩陣的形成 .......................................................13
2.3.3 原始數據與解............................................................19
2.3.4 各種限制與OLTC分接頭動作的考慮..........................................20
2.4 小結 .....................................................................22
第三章連續潮流算法與靈敏度分析 ..............................................23
3.1. 負荷增長方式與發電機功率增長的分配 ......................................23
3.2. 采用延拓法的潮流算法.....................................................25
3.2.1 潮流方程以及雅可比矩陣的修改............................................25
3.2.2 預測和校正過程..........................................................26
3.3 靈敏度分析 ...............................................................30
3.3.1 基于連續潮流的簡單靈敏度分析............................................30
3.3.2 基于特征值－特征向量的靈敏度與穩定性分..................................31
3.4. 小結 ....................................................................32
第四章故障情況下的甩負荷方案.................................................33
4.1. 電壓穩定性故障 ..........................................................33
4.1.1 線路停運 ...............................................................33
4.1.2 發電機的停運 ...........................................................34
4.1.3 故障類型與甩負荷策略....................................................34
4.2. 切負荷地點的確定.........................................................35
4.2.1 概述 ...................................................................35
4.2.2 負荷類型的考慮..........................................................36
4.3. 切負荷量的確定...........................................................36
4.3.1切負荷的理論目標量 ......................................................36
4.3.2 實際切負荷量 ...........................................................37
4.4. 最佳切負荷方案...........................................................38
第五章測試系統與計算結果 ....................................................40
5.1. 測試系統.................................................................40
5.1.1 系統接線圖..............................................................40
5.1.2 正常運行狀態的潮流分布..................................................40
5.2. 連續潮流計算結果........................................................ 41
5.2.1 不考慮發電機各種極限時的計算結果........................................41
5.2.2 考慮發電機原動機輸出極限時的計算結果 ...................................45
5.2.3 考慮發電機電樞電流極限時的計算結果 .....................................46
5.2.4 影響負荷功率極限的因素 .................................................47
5.3. 故障切負荷計算結果 ......................................................48
5.3.1 線路故障算例 ...........................................................48
5.3.2 發電機故障算例..........................................................50
總  結 .......................................................................52
參考文獻..................................................................... 54
附錄 ........................................................................56

摘 要
電力系統中很多電壓崩潰事故往往是由一些故障引起的，切負荷是使故障后的系統恢復電壓穩定的有效方法。本文對故障切負荷的策略作了一些研究，提出了一種切負荷的方法。為了更準確地描述電力系統在非正常運行情況的狀態，本文提出了一種新型的潮流算法，它同時考慮了系統的網絡方程和動態元件的穩態特性，使計算結果更接近系統實際運行狀態。另外還設計了基于延拓法的連續潮流算法，用于求取系統的穩定極限，和計算節點的電壓穩定靈敏度。在此基礎上，本文提出了選取切負荷地點和確定最小切負荷量的方法。
關鍵詞：電力系統 電壓穩定 電壓崩潰 連續潮流 切負荷。
Abstract
In power system, many voltage collapse incidents are caused by some fault, load shedding is a efficient way to restore the stability of a system after fault. In this paper we make some study on load shedding strategy after fault and a load shedding method is presented. In order to describe the state of a power system under abnormal operation condition more accurately, a novel load flow algorithm is developed in which both network equation and the steady characteristic of dynamic elements in power systems are considered. Also we developed a continue-power-flow (CPF) program based on the method which is used to calculate the stability limit of a power system and the voltage stability sensitivity of a special bus. Based on the above, a method used to select the location and determine the amount of a load shedding strategy is presented.
Keywords: Power system Voltage stability Voltage collapse Continue power flow Load shedding.